JP-A-2000-173709 (Patent Document 1) discloses a waterproof connector of this type. The disclosed waterproof connector will be briefly described with reference to FIG. 1. A seal ring 3 is fitted over an outer periphery of a housing body 1 at a rear end of a hood portion 2 which is provided around the housing body 1 on its front end 1a side. A retainer insertion groove 4 is formed in a side surface of the housing body 1 in front of the fitting position of the seal ring 3. A retainer 5 is inserted into the retainer insertion groove 4 through a window hole (not illustrated) which is opened in a side surface of the hood portion 2 at a position corresponding to the retainer insertion groove 4. The retainer 5 is held at a temporary locking position where the retainer 5 allows insertion and removal of terminal metal fittings 6A and 6B and at a real locking position where the retainer 5 locks into recessed portions 7 of the terminal metal fittings 6A and 6B, respectively. Operation of the retainer 5 is carried out from the front side of the housing body 1.